Wallboard butt joint preparation

ABSTRACT

The preparation of a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide smooth planar butt joints includes the use of a rotary tool having a tool bit to form a channel extending on both sides of the butt joint after the wallboard panels have been installed. After the formation of the channel, spackling of the butt joint in a conventional manner results in a smooth planar finished surface.

BACKGROUND OF THE INVENTION

[0001] This invention relates to the installation of wallboard panels and, more particularly, to the preparation of a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide a smooth planar butt joint.

[0002] Panels of wallboard are formed as a sandwich of a gypsum core between a paper backing and a paper facing and are manufactured in various lengths and widths. During manufacturing, each of the long edges of each panel is tapered on its face, whereas each shorter edge, or butt, is not. When two such panels are abutted against their long edges, the tapered edges form a channel which can be filled with spackling compound which can be smoothed and sanded to form a continuous planar surface which hides the joint. However, when two such panels are abutted along their butt ends, there is no channel for receiving the spackling compound. Therefore, in the past, to make the butt joint less noticeable and more aesthetically pleasing to the eye, it has been conventional practice to widen and feather the joint to an extreme length, sometimes as long as five feet in width. Nevertheless, a curve still remains on the wall or ceiling. For optimum aesthetics, especially when such a butt joint is adjacent to a non-perpendicular wall or ceiling, the curve is problematic.

[0003] Various solutions have been proposed to remove the curvature of butt joints, but to the applicant's knowledge none has achieved commercial success. U.S. Pat. No. 4,584,224 to Schneller addresses this problem by using a saw to remove core material along the butt edge of a non-installed wallboard panel and then downwardly bending the remaining thin layer of facing to form a taper. U.S. Pat. No. 5,799,458 to Ferguson and U.S. Pat. No. 5,832,684 to Trout et al both propose using a back support between studs to which wallboard panels are mounted, curving the wallboard panels into the back support and filling in the recessed portion with spackling compound. However, none of these proposals has proven to be satisfactory for a number of reasons. Thus, since Schneller cuts a groove prior to installation of the wallboard panel, the subsequent attachment of a panel to an underlying stud by nails or screws results in the destruction of the face layer. The proposals of Ferguson and Trout et al require the purchase and installation of a back support for each and every butt joint. Further, the recessed joint has a width of approximately twelve inches which must be filled with spackling compound. Accordingly, a need exists for a way to prepare a butt joint of two adjacent wallboard panels which is easy to implement, is inexpensive, and does not suffer from any of the drawbacks discussed above.

SUMMARY OF THE INVENTION

[0004] In accordance with the principles of this invention, a pair of wallboard panels are secured in place to an underlying support to form a butt joint therebetween. A rotary tool with a tool bit having a peripheral cutting edge is then utilized to form a channel in the pair of panels parallel to their abutting edges and extending substantially equally in both of the panels. Accordingly, this channel can be filled with spackling compound and then finished to form a smooth planar surface which hides the joint.

[0005] In accordance with an aspect of this invention, when the panels are secured to the underlying support, a gap of a predetermined width is provided between the butt edges of the panels. The rotary tool is provided with a guide projection having a dimension equal to the predetermined width of the gap, and when the tool is used to form the channel, the guide projection is inserted into the gap and the tool is moved while keeping the guide projection in the gap.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof are identified by the same reference numeral and wherein:

[0007]FIG. 1 is an exploded perspective view of a rotary tool according to the principles of this invention;

[0008]FIG. 1A is a perspective view showing the inventive router bit from the side opposite that shown in FIG. 1;

[0009]FIG. 2 is a perspective view showing a spacer utilized when practicing the present invention;

[0010]FIG. 3 shows a first step in the practice of the present invention;

[0011]FIG. 4 is an enlarged view showing a second step in the practice of the present invention;

[0012]FIG. 5 is a view showing another step in the practice of the present invention;

[0013]FIG. 5A is a cross sectional view taken along the line 5A-5A in FIG. 5;

[0014]FIG. 6 is a view showing a further step in the practice of the present invention;

[0015]FIG. 7 is a view showing the final product after the practice of the present invention; and

[0016]FIGS. 8 and 9 are cross sectional views showing an alternate method according to the present invention.

DETAILED DESCRIPTION

[0017] Referring now to the drawings, FIGS. 1 and 1A disclose an inventive tool which may be utilized in practicing the present invention to prepare a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide a smooth planar butt joint. The tool, designated generally by the reference numeral 10, is illustratively a modified Rotozip® spiral saw 12 having a bit-receiving chuck 14 on an output shaft 16 of the tool 12. A collar 18 is mounted to the tool 12, as by the screws 20, to surround the chuck 14. The collar 18 includes a pair of guide fins, or projections, 22, 24 which are on opposite sides of the output shaft 16 and extend radially outwardly from the shaft 16. The tool 10 further includes a tool bit 26 having a bit shaft 28 receivable in the chuck 14. Illustratively, the tool bit 26 is a router-type bit and includes a disc 30 secured orthogonally to the shaft 28. On the periphery of the disc 30 are a plurality of cutting edges 32. Each of the cutting edges 32 is at an angle to the bit shaft in a range from about 0° to about 90°, and preferably is at a 45° angle to the router shaft 28. The tool bit 26 has an overall diameter in the range from about 0.25 inch to about 2.00 inches and the cutting edges 32 provide a kerf, or depth of cut, in the range from about {fraction (1/32)} inch to about ⅜ inch.

[0018] Use of the tool 10 is relatively simple in order to prepare a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide a smooth planar butt joint. Preferably, at least one of the spacer elements 34 shown in FIG. 2 is utilized. The spacer element 34 is an angle bracket having a pair of countersunk holes 36 on its front side. Illustratively, the spacer 34 is approximately ⅛ inch thick. According to the present invention, the wallboard panels are prepared after they are secured in place. Thus, as shown in FIG. 3, the wallboard panel 38 is secured to an underlying support 40, illustratively a two-by-four wooden stud. Such securing is done in a conventional manner, such as by adhesive, nails or screws, or a combination of adhesive and either nails or screws. The underlying support 40 can alternatively be a metal stud. In this case, screws are used to secure the wallboard panel 38. In any event, after the wallboard panel 38 is secured to the stud 40 with its butt edge 42 overlying the stud 40, a pair of spacer elements 34 are secured to the wallboard panel 38, as by screws 44 extending through the holes 36 (FIG. 4). After the spacers 34 are installed, the second wallboard panel 46 is secured to the stud 40 with its butt edge 48 in contact with the spacers 34. Securing the wallboard panel 46 to the stud 40 is done in the same manner as for the wallboard panel 38. Accordingly, the wallboard panels 38, 46 are secured to the stud 40 with their butt edges 42, 48 being parallel and separated by a gap 50 approximately ⅛ inch in width. The spacers 34 can also be used by using the holes 36 as templates to ensure the correct placement of the nails and/or screws securing the wallboard panels to the stud.

[0019] The next step in preparing the butt edges 42, 48 for receiving spackle is to utilize the tool 10 to cut a channel along the edges 42, 48 which is parallel to the edges 42, 48 and extends substantially equally in both of the wallboard panels 38, 46. To do this, the bit 26 is secured in the chuck 14 so that the cutting edges 32 extend outwardly beyond the front face of the collar 18 the desired depth of cut. According to a first way of practicing the present invention, this depth of cut is chosen to remove the face paper and a small amount of the core material from the wallboard panels 38, 46. Before using the tool 10, the spacers 34 are removed. The tool 10 is then positioned so that the guide fins 22, 24 are within the gap 50. Preferably, the width of the guide fins 22, 24 is slightly smaller than the width of the gap 50 to allow the guide fins 22, 24 to move freely within the gap 50. Illustratively, the width of each of the guide fins 22, 24 is about {fraction (1/64)} inch less than the width of the gap 50. With the tool 10 turned on, it is moved along the length of the edges 42, 48 to form the desired channel 52 as shown in FIGS. 5 and 5A. As illustrated, the tool 10 removes a narrow strip of the face paper 54 from the wallboard panel 38 and a narrow strip of the face paper 56 from the wallboard panel 48 flanking the gap 50, as well as some of the core material of the panels 38, 46 underlying the removed strips of face paper. It will be appreciated that when the wallboard panels are secured to a metal stud, the bit diameter is chosen so that the securing screws are outside the resulting channel.

[0020] After formation of the channel 52, spackle is placed in the channel 52 and a hand roller (not shown) may be used along the edges of the channel 52 to smooth the edges of the face paper 54, 56, which was left in a slightly frilled state by the tool 10. The roller compresses the cut edges of the wallboard panels to eliminate the ridge formed when the face paper is removed. A narrow piece of spackling tape 58 is then placed in the channel 52 and the roller is used again to adhere the spackling tape 58 to the spackle in the channel 52. Spackling is then applied over the tape 58, in a conventional manner, and is then smoothed and sanded, again in a conventional manner, to provide a smooth planar surface, as shown in FIG. 7.

[0021]FIGS. 8 and 9 illustrate an alternative use of the tool 10. As shown in FIG. 8, the depth of cut of the router bit 26 is adjusted so that the router bit 26 cuts a channel 60 just below the surface of the face paper 54, 56 of the wallboard panels 38, 46. In this manner, only core material of the wallboard panels 38, 46 is removed. After the channel 60 is cut, spackle 62 is placed in the channel 60 and the roller is used to move the unsupported edges of the face paper 54, 56 into the channel 60 in contact with the spackle 62. More spackle and spackling tape 64 are then applied and the joint is again finished in a conventional manner.

[0022] Accordingly, there has been disclosed an improved tool and method for preparing a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide smooth planar butt joints. This preparation is done after the wallboard panels are installed in place, is very time efficient and results in a smooth planar butt joint. While illustrative embodiments of the present invention have been disclosed herein, it is understood that various adaptations and modifications to the disclosed embodiments are possible and it is therefore intended that this invention be limited only by the scope of the appended claims. Thus, other shaft mounted devices, such as a spiral saw or an abrasive cutter, can be utilized to produce the desired effect of cutting a channel in the core of the wallboard to practice this invention. 

What is claimed is:
 1. Apparatus for preparing a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide a smooth planar butt joint, comprising: a rotary tool having a bit-receiving chuck on an output shaft of the tool; a collar mounted to said tool and surrounding said chuck, said collar having a first guide fin extending radially from the output shaft; and a tool bit having a peripheral cutting edge and a bit shaft adapted for receipt in said chuck.
 2. The apparatus according to claim 1 wherein the tool bit further includes a disc secured orthogonally to the bit shaft and wherein the cutting edge is secured to the periphery of the disc.
 3. The apparatus according to claim 1 wherein the collar comprises a second guide fin extending radially from the output shaft on the other side of the output shaft from the first guide fin.
 4. The apparatus according to claim 1 wherein the cutting edge is at an angle to the bit shaft in the range from about 0° to about 90°.
 5. The apparatus according to claim 4 wherein the cutting edge is at a 45° angle to the bit shaft.
 6. The apparatus according to claim 1 wherein the tool bit has a diameter in the range from about 0.25 inch to about 2.00 inches.
 7. The apparatus according to claim 1 wherein the tool bit has a kerf in the range from about {fraction (1/32)} inch to about ⅜ inch.
 8. A method for preparing a pair of abutting straight edges of a pair of wallboard panels for receiving spackle to provide a smooth planar butt joint, comprising the steps of: securing in place to an underlying support a first of the pair of panels having a first of the pair of edges; securing in place to the underlying support the second of the pair of panels having the second of the pair of edges, with the first and second edges being parallel one to the other; providing a rotary tool with a tool bit having a peripheral cutting edge; and using the rotary tool to form a channel in said pair of panels parallel to said first and second edges and extending substantially equally in both said pair of panels.
 9. The method according to claim 8 wherein: the step of securing the second panel includes the step of providing a gap of a predetermined width between the first and second edges; the step of providing a rotary tool includes the step of providing a guide projection for the tool bit, wherein the guide projection has a dimension slightly less than said predetermined width; and the step of using the rotary tool includes the steps of: inserting the guide projection into the gap; and moving the tool while keeping the guide projection in the gap.
 10. The method according to claim 9 wherein the step of providing a gap includes the step of utilizing a spacer.
 11. The method according to claim 10 wherein the step of utilizing a spacer includes the step of utilizing a spacer having a thickness in the range from about {fraction (1/32)} inch to about 1-{fraction (1/2)} inches.
 12. The method according to claim 11 wherein the step of utilizing a spacer includes the step of removing the spacer after the step of securing the second panel and before the step of using the rotary tool.
 13. The method according to claim 8 wherein the step of using the rotary tool includes the step of moving the tool bit below the face paper of the pair of wallboard panels so as to remove core material from the pair of wallboard panels without removing the face paper.
 14. The method according to claim 8 further including the step of using a roller to apply pressure to the edges of the channel. 